Method for the manufacture of a saddle made of composite material, in particular for a bicycle

ABSTRACT

Saddle made of composite material, in particular for a bicycle, comprising a support structure provided with a padding having a seating surface. The support structure comprises a plurality of first layers of high-rigidity composite material having an opening formed centrally therein and a second layer of composite material with a rigidity less than that of the first layers, fixed to the latter along a superimposed surface covering the opening so as to form an elastically yielding zone which is preferably located in the prostatic and ischiatic zones of the seat of the saddle.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a division of U.S. application Ser. No. 10/276,009, filed Nov. 12, 2002, which is a 371 of PCT/IB01/01352, filed Jul. 27, 2001.

TECHNICAL FIELD

The present invention relates to a saddle made of composite material, in particular for a bicycle, and to a method for the manufacture thereof.

BACKGROUND ART

As is known, saddles of the more conventional type are generally composed of a shaped, rigid or semi-rigid body which forms the support structure of the saddle and is referred to, in the technical jargon of the sector, by the name of “shell”, and of a padding which is arranged on top of the shell and generally consists of an expanded elastomer material such as, for example, polyurethane with or without the addition of material in the form of a gel. The shell also has, mounted underneath it, fixing means for ensuring the connection of the saddle with the frame of the bicycle. These means normally comprise a shaped bar (or a pair of shaped bars) fixed to the saddle mounting tube by means of clamps.

The padding of the saddle is generally lined with a fabric, leather or other material which essentially performs the function of ensuring a greater seating comfort for the cyclist.

As is known, in the bicycle sector, for some time there has been a particularly pressing need to provide saddles which are at the same time comfortable, i.e. are able to ensure seating comfort, and light so as not to penalize excessively the cyclist's performance.

In order to provide saddles which are particularly light, saddles without padding have been manufactured recently, said saddles being essentially composed of the support structure alone which is integrally made of particularly strong and light materials such as, for example, composite materials consisting of carbon fibres bonded together in resin matrices.

These saddles, although being extremely light and having a good mechanical strength, in practice have proved to be excessively uncomfortable owing to the limited elasticity of the seat.

In order to improve the comfort of cyclists, more recently thin paddings have been mounted on top of the carbon-fibre seats, although these still have been unable to solve entirely the problem of excessive lack of comfort.

Alternatively, already known saddles envisage the use of a padding which is composed of several layers of material with varying elasticity (including also gel) which are suitably arranged in the various zones of the seating surface above the support structure which is made of rigid or semi-rigid plastic material (for example polypropylene) with a substantially constant cross-section. In this way, the distribution of the pressures over the whole of the seating surface of the saddle has been significantly improved, thereby benefiting the comfort of the cyclist, but greatly penalizing the overall lightness of the saddle.

At present, therefore, the problem of providing a saddle which is both comfortable and extremely light has not been entirely solved.

In particular, hitherto the function of optimising the seating comfort has been attributed entirely to the padding and the function of reducing, where possible, the overall weight of the saddle has been attributed to the support structure.

U.S. Pat. No. 3,604,748 discloses a bicycle saddle of composite material. However, such a prior bicycle saddle has a rather rigid support structure of reduced comfort and relatively high weight.

DISCLOSURE OF THE INVENTION

The main object of the present invention is therefore that of eliminating the drawbacks of the abovementioned art by providing a saddle made of composite material—in particular for bicycles—which is extremely light and has a very comfortable seating surface.

Another object of the present invention is in particular that of providing a saddle which is constructionally simple and operationally entirely reliable.

A further object of the present invention is that of providing a simple and low-cost method for producing a comfortable and light saddle.

These objects, along with others, are all achieved by a saddle, in particular for a bicycle, which comprises a support structure provided with a padding having, associated above it, a seating surface, the support structure comprising at least one first layer of composite material and at least one second layer of composite material having a form different from that of the first layer and fixed thereto along a superimposed surface of the layers, to define portions with varying rigidity on the support structure, wherein the saddle comprises a plurality of first layers which are superimposed and fixed together, each of the first layers defining at least one opening inside which the second layer is located so as to provide an elastically yielding zone.

By virtue of the above arrangement according to the invention it has been possible to combine the features of comfort and lightness in a single saddle.

BRIEF DESCRIPTION OF THE DRAWINGS

Further features and advantages of the invention will be more clearly understood from the detailed description of a preferred embodiment of the saddle which follows, furnished by way of non-limiting example with the assistance of the accompanying drawings in which:

FIG. 1 shows a plan view of the saddle according to the present invention with some parts removed so that others may be seen more clearly;

FIG. 2 shows a cross-sectional side view of the saddle according to FIG. 1;

FIG. 3 shows in schematic form a side view, on a larger scale and cross-sectioned, of the support structure of the saddle according to FIG. 1;

FIG. 4 shows in schematic form a cross-sectional view of the support structure along the line II—II of FIG. 2.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)

In accordance with the figures of the accompanying drawings, 1 denotes in its entirety the saddle forming the subject of the present invention.

Below reference will be made, for the sake of simplicity of the description, to a saddle for bicycles, it being understood, however, that it may also be mounted on cycles, motorcycles or other vehicles of any kind.

The saddle 1 is essentially composed of a rigid or semi-rigid frame 2 forming the support structure of the saddle and referred to in the technical jargon of the sector by the name of “shell”, and of an elastically yielding padding 3 mounted on top of the shell 2 and consisting preferably of an expanded elastomer material.

Preferably the padding 3 is made using an expanded elastomer material (polyurethane) with or without injection of material in gel form and is covered with a lining of fabric, leather or other material able to limit the amount of sweating of the cyclist.

With particular reference to the accompanying FIG. 2, the shell 2 has a bottom surface 4 to which are connected fixing means able to ensure the connection of the saddle 1 with a support frame of the bicycle (not shown since of the type known per se) and an upper surface 6 onto which the padding 3 able to define at the top the seating surface 7 for the cyclist is fixed.

The fixing means, which are not shown in the accompanying figures, are generally obtained by means of a shaped bar which is folded onto itself (fork) or by means of a pair of shaped bars which are fixed to the saddle mounting tube by means of clamps.

Advantageously, these shaped bars will be made of carbon fibre and will have variable cross-sections, in particular a wider cross-section in the region of the saddle mounting tube in order to allow for the various tensional forces to which it is subject.

According to the invention, the support structure 2 is formed by means of one or more first layers 8 consisting of high-rigidity composite material and by means of a second layer 9 consisting of lower-rigidity composite material which is fixed to the first layer 8 along a superimposed surface 10. The first and the second layers 8 and 9 cover different areas and therefore define portions of varying rigidity.

More particularly, in accordance with a preferred embodiment of the present invention, the support structure 2 is composed of a plurality of first layers 8 each provided with an opening 11 located substantially in a central zone of the saddle 1. This opening 11 is covered only by the second lower-rigidity layer with a relatively high elasticity. Thus an elastically yielding zone is defined in the region of this opening 11.

Obviously, without departing from the scope of protection of the present invention, it will nevertheless be possible to cover the opening 11 with a first layer 8 instead of a second layer 9 with less rigidity since the elastic effect which can be associated with this zone may in any case be obtained owing to the smaller number of layers of composite material, i.e. to the reduced thickness of the support structure 2 in the region of this opening 11.

Advantageously, this elastically yielding zone is positioned in the prostatic zone of the seat 7 of the saddle 1 and/or in the ischiatic zones of the seat 7 of the saddle 1.

For this purpose, this elastically yielding zone may, for example, have a form comprising two rear lobes 11′ located in the ischiatic zones of the seat 7 of the saddle 1 and a central lobe 11″ extending in the prostatic zone of the seat 7 of the saddle 1.

Structurally, as shown in the accompanying FIGS. 3 and 4, the first layers 8 have a substantially similar form and dimensions which become smaller layer-by-layer so as to create a support structure 2 of variable thickness, which is thinner along its peripheral edge.

In accordance with the example of embodiment illustrated in FIGS. 3 and 4, the second layer 9 is fixed between two first layers 8.

Constructionally the first layer 8 preferably consists of carbon fibres bonded to an epoxy matrix (and more generally composite-material fibres commonly called “high-modulus fibres”), while the second layer 9 consists of kevlar and polyester fibres bonded to a polyurethane-based matrix (and more generally composite-material fibres commonly called “high-elongation fibres”). In this way the first layer has a relatively high rigidity, while the second layer has a relatively high elasticity.

Advantageously, moreover, the fibres which make up the various first layers 8 may be oriented in variable directions in order to obtain the maximum mechanical performance.

In particular, for example, alternate first layers 8 with fibres oriented longitudinally, transversely and at 45° with respect to the longitudinal axis of the saddle may be envisaged.

The second layer 9 will have preferably a longitudinal orientation of the kevlar fibres and a transverse arrangement of the polyester fibres.

The present invention also relates to a method for the manufacture of a saddle 1 made of composite material, in particular for a bicycle, of the type comprising conventionally a step involving moulding, in a mould, of the polyurethane cover 3 on the support structure 2.

More particularly, a mould consisting of a male part, to which the support structure is applied, and a female part, which is suitable covered with a lining, is used during this step.

The abovementioned moulding step then envisages the insertion of polyurethane into the mould and closing of the latter.

According to the method in question, the manufacture of the support structure 2, intended to be inserted into the mould once formed, comprises a step involving hollow-punching of the first layers 8 made of fabric consisting of a high-rigidity composite material with simultaneous or subsequent formation of the opening 11 in each layer 8.

The various first layers 8 will preferably have dimensions which are slightly different and gradually decreasing, while maintaining the same central opening 11. For this purpose, hollow punches with a cutting blade defining different sections may be envisaged for example.

Similarly, hollow-punching of a second layer of fabric consisting of a composite material with a rigidity less than that of the first layer will also be envisaged, without, however, the formation of openings therein.

At this point, there will follow a step involving the superimposition, on top of each other, of the first layers 8 having different dimensions in such a way as to ensure that the central opening 11 is well-defined, creating a thinning effect along the edges.

Finally, there will follow a step involving the moulding and fixing of th e various layers 8 and 9 inside a special mould by means of a thermosetting resin.

The first layers 8 are advantageously pre-impregnated with an epoxy resin which is able to cross-link rapidly at a temperature of between 70° and 100° C. The second layer 9 is also advantageously of the type pre-impregnated with resin (for example polyurethane) and therefore once the layers 8 and 9 have been placed in the mould, the latter is closed with a suitable pressure and, by means of heating and cooling means associated therewith, complete moulding of the support structure is performed.

Advantageously, during this mould forming step, the grooves and the lugs necessary for mounting subsequently the fixing means and in particular the shaped bars are also formed on the bottom surface 4 of the support structure 2.

In accordance with the example of embodiment illustrated in FIGS. 3 and 4, during the superimposition step, firstly a first layer 8 is arranged in the mould, then a second layer 9 is superimposed on this layer and the remaining first layers 8 are superimposed on the latter.

The mutual fixing of the layers inside the mould may be achieved as a result of the thermosetting resin with which the said layers are impregnated or by means of injection of resin inside the mould.

Advantageously the support structure 2, once extracted from the mould, may undergo finishing steps aimed at eliminating, for example, the presence of any burrs.

The invention thus conceived therefore achieves the pre-set objects.

Obviously, it may assume, in its practical embodiment, forms and configurations different from that illustrated above without, thereby, departing from the present scope of protection.

Moreover, all the details may be replaced by technically equivalent elements and the dimensions, the forms and the materials used may be of any nature depending on requirements. 

1. A method of manufacturing an integral saddle, comprising: hollow-punching a plurality of first layers of high-rigidity composite material including high-modulus fibers, so as to define a profile of a support structure and at least one opening in each of said first layers; hollow-punching at least one second layer made of high-elasticity composite material including high-elasticity fibers and having a rigidity less than that of said first layers, so as to leave said at least one second layer substantially imperforate; superimposing said first layers and said at least one second layer inside a first mold so as to ensure an alignment of the openings in said first layers, a portion of said at least one second layer being disposed coextensively with said openings so as to cover or block said openings; molding and fixing said first layers and said at least one second layer inside said first mold by means of a thermosetting resin, so as to provide an elastically yielding zone in the region of said openings to form said support structure; extracting said support structure from said first mold; inserting said support structure into a second mold; and expanding an elastomer material in said second mold to form a cover over a top of said support structure to obtain said integral saddle.
 2. The method according to claim 1, wherein the superimposing includes arranging at least one of said first layers inside said first mold, superimposing said at least one second layer on top of said one of said first layers and superimposing remaining ones of said first layers on top of said at least one second layer.
 3. The method according to claim 1, wherein the molding and fixing of said first layers and said at least one second layer inside said first mold includes pre-impregnating said first layers and said at least one second layer with said thermosetting resin.
 4. The method according to claim 1, wherein the molding and fixing of said first layers and said at least one second layer inside said first mold includes injecting resin inside said first mold.
 5. The method according to claim 1, wherein said first layers are hollow-punched to have different dimensions to create a thinning or tapered effect along edges of said support structure while maintaining unchanged said openings.
 6. The method according to claim 1, wherein the superimposing is so effected that said at least one second layer is interposed between two of said first layers.
 7. A method of manufacturing an integral saddle, comprising: hollow-punching at least one first layer of high-rigidity composite material including high-modulus fibers, so as to define a profile of a support structure and at least one opening in said at least one first layer; hollow-punching at least one second layer made of high-elasticity composite material including high-elasticity fibers and having a rigidity less than that of said at least one first layer, so as to leave said at least one second layer substantially imperforate; superimposing said at least one first layer and said at least one second layer inside a first mold so that a portion of said at least one second layer is disposed coextensively with said opening so as to cover or block said opening; molding and fixing said at least one first layer and said at least one second layer inside said first mold by means of a thermosetting resin, so as to provide an elastically yielding zone in the region of the covered or blocked opening to form said support structure; extracting said support structure from said first mold; inserting said support structure into a second mold; and expanding an elastomer material in said second mold to form a cover over a top of said support structure to obtain said integral saddle.
 8. The method according to claim 7, wherein the molding and fixing of said at least one first layer and said at least one second layer inside said first mold includes pre-impregnating said at least one first layer and said at least one second layer with said thermosetting resin.
 9. The method according to claim 7, wherein the molding and fixing of said at least one first layer and said at least one second layer inside said first mold includes injecting resin inside said first mold. 